Heterocyclic spiro-naphthalenones. Part IV. Synthesis of some 3,4-dihydrospiro [naphthalene-2(1H),2′-pyrrolidine]-1-ols from 3,4-dihydrospiro [furan-2(5H),1′(2′H)-naphthalene]-2′,5-dione

Depending on the experimental conditions the spirolactone 3 on treatment with methylamine gave compounds 6, 7 or the rearranged product 4 . Compound 4 was used to prepare the title compounds 11–13, 15, 18–20 and other derivatives.